haerison



(No Model.) 2 Sheets-Sheet 1.

H. T. HARRISON. MEANS AND APPARATUS FOR DISTRIBUTING ELECTRICITY.

N0. 529,265. Patented Nov. 13, 1894.

2 Sheets-Sheet 2.

(No Model.)

,H. T. HARRISON. MEANS AND APPARATUS FOR DISTRIBUTING ELECTRICITY.

UNITED STATES PATENT OFFICE.

HAYDN THIES HARRISON, OF LONDON, ENGLAND.

MEANS AND APPARATUS FOR DISTRIBUTING ELECTRICITY.

SPECIFICATION forming part of Letters Patent No. 529,265, dated November13, 1894.

Application filed January 19, 1894. Serial No. 497,452. (NomodeL)Patented in England December 22,1893-1I0. 23.674-

To all whom it may concern.-

Be it known that I, HAYDN THIES HARRI- SON, a subject of the Queen ofGreat Britain and Ireland, residing at Dorchester Place, in the city ofLondon, England, have invented Improvements in Distributing Electricityand Means or Apparatus for the Purpose, of

which the following is a specification, and for which Letters Patenthave been granted in Great Britain, dated the 22d day of December,1893,No. 23,674.

The ordinary systems of electrical distribu tion (excluding the directhigh tension, rarely used) may be divided into two classes, the directlow tension system and the alternating high tension (transformer)system. Each of these has its advantages and disadvantages.

An advantage of the low tension system lies in the fact that practicallyall the energy produced during light loads is registered on theconsumers meters, appreciable loss in the mains occurring only duringheavy loads, and as the station is ordinarily running a light load onthe average probably some sixteen hours out of the twenty-four, itbecomes obvious that the system has a good day-load efliciency,especially as accumulators may be used during the day, and steam be shutdown altogether. On the other hand the low tension system is onlypracticable over a com: paratively small area. The conductors laid downhave to be capable of carrying the maximum load, thus absorbing a largeamount of capitalinmains. During heavy loadsinuchof the energy is wastedin'heating these mains, and moreover, the large direct-current dynamosnecessary for the system, are costly to make, and suffer considerablyfrom wear and tear.

The alternating high tension (transformer) system has a high plantefficiency during medium and heavy loads, but during the day time thereis more energy lost in magnetizing the transformers than is consumed inlight by the consumers at the time. Hence, with this system, there ishigh efficiency during heavy loads and low efficiency during lightloads. Moreover the system has the advantage that it is able-todistribute its energy over alarger area, and involves less outlay ofcapital in mains and transformers than is involved in providing themains of a corresponding low tension system.-

Now my invention has reference to a system in which the foregoing twosystems are combined, and which is adapted to admit of running, when alight load is on (for example during the day), with a low tensiondynamo, or accumulators, direct on to the consumers lights; and, whenthe load begins to increase, of switching over onto a high tensionalternator, which will feed the consumers lights through transformers inthe ordinary manner. For these purposes, I provide in counection withthe primary and secondary mains, switches adapted to automatically throwthe respective transformers into circuit directly the low tensioncurrent is switched olf, and before the high tension alternating currentis switched on; and to cutout the transformers, and connect theconsumers or secondary mains direct on to the service or primary mains,directly the high tension current is switched off and the low tensioncurrent switched on.

In carrying out my invention,Iemploy automatic switches, such that theautomatic changes will take place as rapidly as practicable, so as tominimize the blink in the light. In order to eifect this I takeadvantage of the retardation of the alternating current, due toself-induction, and also of the repulsion of copper rings and shortcircuited coils from magnets excited by an alternating current.

In the accompanying drawings, Figures 1, l, 2 and 3, are diagrammaticviews illustrating three arrangements of apparatus for carrying out myinvention.

In the arrangement shown in Fig. I each transformer l, or bank oftransformers, either in a consumers house, or in a distributing station2,is provided with an automatic switch comprising a lever 3 witharmature on which are fixed four copper connecting pieces or staples 4:,l, 4, 4 two on each side of the fulcrum 3, and four pairs of contacts 5,5, 5, 5 for example mercury cups, so arranged (as shown), that there aretwo pairs on each side of the fulcrum of the lever, and so that eachconnecting piece or staple can, when depressed, connect up one suchpair.

One arm of the lever 3 is loaded so that the two connecting pieces 4, 4,on that arm will remain in the corresponding two pairs of mercury cups5, 5, except when the loaded end of the lever is attracted by an electromagnet G placed above it. This electro-magnet is wound with very finewire 7, and the iron forming its core is carefully laminated, so as tomake it a very eflicient choking coil. The magnet winding 7 is connecteddirect across the primary or service mains 8, 8 as shown.

The two pairs of mercury cups 5, 5 under the loaded end of the lever,are so connected that when the electro-magnet 6 does not attract thearmature or lever 3, the connecting pieces 4, 4 being immersed in themercury-in the said cups 5, 5, will respectively connect the primary 1of the transformer, to the primary or service main 8, and the secondary1 of the transformer, to the secondary or consumcrs main 9 through theconductors shown. The other end of the lever 3 being then raised, theconnecting pieces 4, 4 carried thereby, will be, out of the twocorresponding pairs of mercury cups 5", 5, which are insulated from eachother--thus disconnecting the secondary or consumers mains from theprimary or service mains. These two pairs of mercury cups are connectedup in such a way that when the connecting pieces 4, 4, are down, theprimary or service mains 8, 8 from the central station 10 are connecteddirect on to the secondary or consumers mains 9, 9. and the transformeris disconnected. In the example shown, this is effected by connectingone of the mercury cups 5 with the primary main 8 by a conductor 11, andthe other with the secondary main 9 by a conductor] 2 and connecting oneof the mercury cups 5 with the primary main 8 by a conductor 13 and theother to the secondary main 9 by a conductor 14.

15 is a direct low tension current dynamo at the central station 10; orthis dynamo may bev replaced by accumulators.

16 is a high tension alternator.

17 is a double pole two-way switch by which either the dynamo 15, or thealternator 16, can be connected with the primary mains 8, 8.

9* are lamps or other translating devices on the secondary mains.

The action of the arrangement is as follows: Assuming the centralstation 10 to be running with the direct current dynamo 15 for a lightload, and that the mains 8, 8*, laid down for the high tension current,are capable of carrying the current necessary to light the lamps direct,then, when the load, as shown by the ammeter at the station, increasesto a suitable amount, the high leusion alternator 16 is started, and theload switched by the switch 17 from the direct low tension currentgenerator 15 to the high tension alternating cur rent generator 16, theswitch 17 then assuming the position shown.

The action of the automatic switch at the distributing station orprivate house 2, or of each such switch where there are several, is

as followsz-VVhile running with adirect low tension current, the electromagnet 6 of the automatic switch will be powerfully energized, therebeing no retardation to the direct current passing through its winding,beyond the ohmic resistance. Consequently it will attract its armature3* and lever 3 and connect the primary or service mains 8, 8 direct ontothe secondary or consumers main 9, 9 by way of .the connecting pieces 44, pairs of mercury cups 5 5, and the conductors hereinbefore mentioned,but immediately the direct low tension fromthe dynamol5isswitched off,there isa momentary break in the primary or service mains 8, 8 whichpermits the weighted end of the lever to fall, and throw thecorresponding transformer 1 into circuit, through the connecting pieces4, 4, pairs of mercury cups 5, 5 and conductors shown, so that directlythe alternating high tension current is switched on, the secondary orconsumers main 9 9 will be served by the transformer, the retardation ofthe electro-magnet 6 with alternating current being then so high, due toself induction, that it is unable to attract the loaded end of the lever3, which serves as its armature,or which is provided with an armature3*. The, electro-magnet 6 can, if desired, be even made to repel thearmature when the alternating current is on, by placing ashort-circuitedwire upon the armature, in a manner that will be readily understoodwithout further description.

The arrangement hereinbefore described may be modified by winding thecore of the electro-magnet 6 of the automatic switch with a secondwinding 7 as shown in Fig. 1. In this case the winding 7 is made ofthick wire and is connected in series with the primary 1 of thetransformer on the primary or service main 8 by the conductors shown.The other winding 7 is made of thin wire, and is connected as a shuntacross the secondary or consumers main 9, 9 as shown. In this modifiedarrangement, when the directlow tension current is switched on, itpasses through the thick wire 7 of the electro-magnet, and through theprimary 1 of the transformer. This causes the electro magnet to attractits armature or lever 3 and lift the loaded end thereof below it,thereby connecting the secondary mains to the primary mains in themanner hereinbet'ore described. The fine wire 7 being connected acrossthe secondary mains, through which the direct low tension current willthen be passing, the electro-magnet will be energized by such currentand willhold the armature up. The weighted end of the lever 3 being thusraised, the primary and secondary windings 1 and l of the transformerwill be disconnected from the mains 8 and 9 respectively. When thedirect low pressure current is switched olf, and the alternating hightension current is switched on, tho armature or lever 3 will fall andconnect the primary Winding 1 of the transformer to the primary orservice main 8, the electro magnet not being then able to attract thearmature or lever owing to the current passing through its thick windingbeing too weak, it being only the primary current of the transformer,while that passing through the fine wire winding on the magnet will thenbe an alternating current and unable to attract the loaded end of thelever for the reason hereinbefore stated. More over by providing thearmature or lever with a short circuited coil, it will be then repelledfrom the said electromagnet.

Fig. 2 is a diagrammatic view illustrating a further arrangement inwhich there are three primary wires 8, 8, 8 from the generating station.The wire 8 is provided at one end with a switch l7 by which it can beconnected either to one pole of the high tension alternating currentdynamo 16, or to one pole of the low tension direct current dynamo 15,or accumulators, as required. This wire is also connected to one end ofthe primary and secondary windings 1, 1 respectively of the transformer(or of each transformer where there are more than one) at thedistributing station or consumers house 2, bya conductor 18, and to one(9) of the secondary or consumers mains 9, Why aconductor 18. The wire 8is connected, or as in the example shown, is adapted to be connected bya switch 17, to the other pole of the alternator 16, or alternators whenseveral are used, and, by a conductor 19 is connected to the other endof the primary winding 1 of the transformer. The third wire 8 isconnected, or as in the example shown, is adapted to be connected by aswitch 17, to the other pole of the direct current dynamo 15, or dynamosor accumulators, and, through the conductor 20, the winding 7 of theelectro-magnet in the automatic switch, and the conductor 21, is con=nected to the secondary or consumers main 9. lVhen switches 17 and 17are used, they I may advantageously be coupled to the switch 17 as shownso that they can be all operated simultaneously. The electro magnet inthis arrangement is also provided with a second winding 7 of fine Wire,as in the last described arrangement, connected across the secondarymains 9, 9. The thick winding 7 in the core can be omitted provided thewinding 7 is connected direct across the mains 18 and 20. I

22 and 23 are conductors by which the other end of the secondary winding1 can be connected to the secondary main 9 through the contact 4,carried by the switch lever 3, and the pair of mercury cups 5. 2% is ameterin circuit with the conductor 18. The automatic switch lever 3 inthis construction is so arranged, as shown, that when the electro magnet6 is energized by switching on the direct low tension current throughthe wires 8", 8, by means of the switch 17, or N -17, the contact piece4, one only of which need be used in this case, will be raised out ofthe mercury cups 5, of which there is only one pair, therebydisconnecting the secondary winding 1 of the transformer from thesecondary or consumers main. When the switch 17, or 17 l7 is moved so asto switch on the alternating high tension dynamo, the high tensioncurrent will pass through the wires 8, 8 conductors 18 and 19, andprimary winding 1 of the transformer, andthe armature and lever 3 willcease to be held up by the electro magnet, and in falling will connectthe secondary or consumers mains 9, 9 to the secondary winding 1 of thetransformer, from which they will then be supplied with electricity, thealternating current then passing through the magnet winding 7 failing,as before, to energize the magnet and attract the switch lever.

Should it not be considered advisable that one end of the primary andsecondary windingsof the transformer be connected together, as shown inFig. 2 when the high tension current is on, an extra pairof mercury cupsand a connecting piece, may be introduced into the automatic switch atthe opposite end of the lever 3 to the pair shown in Fig. 2 and whichlever is then extended to the other side of its fulcrum, theseadditional mercury cups and contact piece serving only to make theconnection when the direct low tensioncurrent is on, and to break theconnection when the high tension alternating current is on. Thismodified arrangement is illustrated in Fig. 3 where 4: is the extraconnecting piece carried by an extension of the switch lever 3; and 5the extra pair of mercury cups, one of which is connected with theconductor 18 by a conductor 25, and the other of which is connected withthe secondary winding 1 by a conductor 26, and also with the secondarymain 9 by a conductor 18. In this modified arrangement the thick winding701' the electro-magnet 6, is connected in series with the primary 1" ofthe transformer, the fine winding 7 being connected across the secondarymains 9, 9 as before. The switch at the central station is also slightlymodified, the lever 17 being elongated in such a way as to makeconnection with an extra contact 27 when the direct low tension currentis switched on so that this extra contact 20 will then be connected tothe main 8 and the mains 8, 8 connected together.

The action of the arrangement is as follows:\Vhen it becomes advisableto switch over to the low tension direct current dynamo 15, the switchis moved over to the rightthus connecting the mains 8, 8, to one pole ofthe low tension dynamo, and the main 8 to the other pole, with theresult that a considerable current will pass along the main 8 throughthe primary of the transformer, through the thick winding 7 of theelectro-magnet 6, and along the conductor 18 and main 8 back to thedynamo 15. The electro magnet 6 will thus be excited and caused tooperate the switch lever 3 so as to cause the connecting piece 4 toconnect the conductor 18 on to the consumers main 9 through theconductor 25, the

-mercury'cups and the conductors 26and 18. The conductor *20 beingalready connected to the primary and secondary mains 8 and 9, acurrentwill pass through the fine wire 7 of the electro magnet 6 andcontinue to excite this magnetuntil such time as the direct current isswitched off.

What I claim is- 1. A combined direct low tension and alternating hightension transformer system of electrical distribution, comprisingprimary and secondary mains, a transformer, direct low tension andalternating high tension current generators, a switching device forthrowing said generators alternately in and out of circuit with saidprimary mains, and an automatically operating switch and circuitconnections whereby said transformer will be rendered inoperative onsaid secondary mains and the primary and secondary mains will beconnected together, when the primary mains are connected with saiddirect current generator, and will be thrown into action and bemaintained in action when said primary mains are disconnected from saiddirect our rent generator and connected with said alternate currentgenerator.

2. In a combined direct 10w tension and alternating high tensiontransformer system of distributing electricity, the combination with theprimary and secondary mains and transformers, of switches adapted toautomatically throw the respective transformers into circuit directlythe low tension current is switched off and before the high tensionalternating currentis switched on, and to cut out the transformers andconnect the consumers or secondary mains direct onto the service orprimary mains directly the high tension current is switched 0d and thelow tension current switched on.

3. In a combined direct low tension and alternating high tensiontransformer system of distributing, electricity, the combination withthe primary and secondary mains and transformers, of circuit connectionswhereby said transformers can be thrown in andout of action, andelectro-magnetic contact making devices for controlling saidconnections, said devices being each operative electrically whentraversed by direct low tension current and inoperative electricallywhen traversed by an alternating current substantially as hereindescribed for the purposes specified.

4. In a combined direct low tension and alternating high tensiontransformer system of distributing electricity, the combination with theprimary and secondary mains and transformers, of switches eachcomprising a loaded lever controlling circuit connections and adapted tonormally place the corresponding transformer in circuit, and an electromagnet adapted to actuate said switch lever to out said transformer outof circuit when its winding is traversed by acontinuons current and tobe inoperative on said switch lever when its winding is traversed by analternating current and to then permit said lever to place saidtransformer in circuit substantially as herein described.

5. In a combined direct low tension and alternating high tensiontransformer system of distributing electricity, the combination with theprimary and secondary mains, transformers, and circuit connections, ofautomatic switches each comprising a switch device controlling saidcircuit connections and adapted when in one position to throw thecorresponding transformer-or bank of transformers into circuit, and anelectro magnet adapted to move said switching device into its oppositeposition and throw said transformer or bank of transformers out ofcircuit, said electro magnet being provided with a winding having alarge self-induction and-connected across one of said pairs of mains,substantially as herein described.

6. In a combined direct low tension and alternating h'gi tensiontransformer system of distributing electricity, the combination with theprimary and secondary mains and transformers, of automatically operatingswitches each comprising a loaded switch lever, circuit connectionscontrolled thereby and by means of which the corresponding transformercan be thrown in and out of action, and an electro magnet adapted toactuate said switch lever in one direction, said electro magnet beingwound with two windings one of which is connected across the primarymains, and the other across the secondary mains substantially as hereindescribed for the purpose specified.

7. Acombined direct low tension and alternating high tension transformersystem of distributing electricity, comprising three pri mary mains, atransformer having its primary connected across two of these mains whichare to serve as the alternating high tension mains, secondary mainsconnected across one of said two primary mains and the third primarymain, direct low tension and alternating high tension currentgenerators, means for alternately connecting the pair of high tensionmains to the alternating current generator, and one of these mains andthe third main to the direct current generator, and an automatic switchadapted to place the secondary of saidtransformer in circuit directlythe low tension current is switched off and to put it out of circuitdirectly the high tension alternating current is switched off and thelow tension current switched on substantially as herein described.

8. A combined direct low tension and alternating high tensiontransformer system of distributing electricity, comprising three primarymains, a transformer having its primary connected across two of thesemains which are to serve as the alternating high tension mains,secondary mains connected across one of said two primary mains and thethird primary main, direct low tension and alternating high tensioncurrent generators, means for alternately connecting the pair of hightension mains to the alternating current generator, and one of thesemains and the third main to one pole of the direct current generator andthe other of the two high tension mains to the other pole of said directcurrent generator and an-automatic switch adapted to place the secondaryof said transformer in circuit directly the low tension current isswitched off and to put it out of circuit directly the high tensionalternating current is switched 0E and the low tension current switchedon substantially as herein described.

' 9. A combined direct low tension and alternating high tensiontransformer system of distributing electricity, comprising three primarymains, a transformer having its primary connected across two of thesemains which are to serve as the alternating high tension mains,secondary mains connected across one of said two primary mains and thethird primary main, direct low tension and alternating high tensioncurrent generators, means for alternately connecting the pair of hightension mainsto the alternating current generatorand one of these mainsand the third main to the direct current generator, circuit connectionswhereby said transformer can be thrown in and out of action, a loadedswitch lever controlling said connections and normally connecting thesecondary winding of said transformer across the secondary mains, and anelectro magnet adapted to actuate said switch lever and disconnect saidtransformer from said secondary mains, said electro magnet having twowindings, one of low resistance connected across the pair of primarymains that serve as the low tension mains, and the other of highresistance connected across the secondary mains, substantially as hereindescribed.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

HAYDN THIES HARRISON.

